Ore-separator.



No. 703,084. Patented June 24, I902.

C. C. PRATT.

ORE .SEPABATOR.

(Application filed June 18, 1901-.)'

2 Sheets Sheet I.

(No Model.)

THE noams PETERS or). mum-Una. WASWNGTUN. o c.

Patented June 24, I902.

C. C. PRATT.

ORE SEPARATOR.

(Application filed June 18, 1901.)

2 Sheets-Sheet 2.

(No Model) m: 0mm FETEFS co. PKOTO-UTHQ, msnmarou. u. c.

UNITED STATES PATENT OFFICE.

CYRUS C. PRATT, OF PORTLAND, OREGON, ASSIGNOR OF ONE-HALF TO THOMASHOLLAND, OF PORTLAND, OREGON.

ORE-SEPARATOR.

SPECIFICATION forming part of Letters Patent No. 703,084, dated June 24,1902.

Application filed June 18,1901. Serial No. 65,041 (No model.)

To all whom it may concern.-

Be it known that I, CYRUS C.PRATT,a citizen of the United States,residing at Portland, in the county of Multnomah and State of Oregon,have invented new and useful Improvements in Ore-Separators, of whichthe following is a specification.

My invention relates to apparatus for washing ores and separatingprecious metals therefrom; and it has for its general object to providean apparatus calculated to automatically separate gold, silver, lead,zinc, and other precious metals from pulverized ore, gravel, loam, orthe like, the said apparatus being highly efficient in practice andrequiring but a minimum amount of attention incident to the separationof the precious metals from the ore, gravel, or loam and but a minimumamount of effort on the part of the attendant or attendants incident tothe cleaning up of the riffle-sluice.

With the foregoing in mind the invention will be fully understood fromthe following description and claims, when taken in conjunction with theaccompanying drawings,

in Which Figure 1 is a view of my improved apparatus with some of theparts partly in side elevation and partly in vertical section and alsowith a machine for collecting the precious metals from fine sand,concentrates, and the like shown as disconnected from the rifflesluice.Fig. l is a view of a box which is interposed between the discharge endof the riffle-sluice and a sluice leading to the tank arranged todischarge into the hopper of a separating machine or vanner precedent tothe cleaning up of the sluice. Fig. 2 is a longitudinal vertical sectionof a portion of the riftle-sluice with the riflles in their properoperative positions. Fig. 3 is aplan view of the same. Fig. 4 is aninverted plan View of one of the riffles. Fig. 5 is a transverse sectionof the riffle-sluice, taken on the line 5 5 of Fig. 2. Fig. 6 is atransverse section of the apparatus, taken on the line 6 6 of Fig. 1 andillustrating the screen for separating rock and coarse gravel from thesmaller portions and preventing the former from entering therifIie-sluice.

Similar letters of reference designate corresponding parts in all of theseveral views of the drawings.

A is a source of water-supply, which may be a reservoir, a dammedstream, or the like.

13 is a sluice or trough mounted on suitable supports and connected withthe source of supply.

O is the riitle-sluice, which is also mounted on suitable supports. andD is a box interposed between the riflie-sluice and the sluice or troughB and disposed below the lower end of the latter, so as to receivetherefrom. The box D is provided, as best shown in Figs. 1 and 6, withan arched screen E, Which serves as a grizzly-that is to say, separateslarge rock and coarse gravel from the smaller portions of the pulp andprevents the former from reaching the riiile-sluice. Such rock andcoarse gravel are discharged from the screen E at the opposite sides ofthe box, while the water, precious metals, and comparatively fineparticles of ore or the like pass through the screen and into the box D.

The riffle-sluice G is preferably composed of a plurality of trough-likeboxes arranged end to end, and since the said sluice may be of anydesired length it is obvious that any suitable number of boxes may beemployed. In the said sluice are arranged a plurality of riffles F,disposed end to end, and when the sluice is formed by boxes, as stated,I prefer to employ a riffle in each box, as illustrated in Figs. 2 and3. The riffies respectively comprise a board a, having oblique slots 1)adjacent to one end and oblique slots 0 of a slightly greater width thanthe slots 5 arranged adjacent to its opposite and lower end and alsohaving comparatively small apertures (Z intermediate of the slots 1) a,transverse strips c, depending from the board at the ends thereof, andzigzag walls f, depending from the board intermediate of the transversestrips e and forming tortuous longitudinal channels g in communicationwith the slots 1) and c and also with the apertures 01. Over each of theriffles F is arranged a finemesh screen G, which corresponds in area tothe board a of the riffle and is suitably connected to said board.

By virtue of the construction thus far described it will be seen thatwhen ore, sand,

loam, or the like is shoveled or otherwise discharged into the sluice ortrough B it will be carried down the latter by the head of water anddischarged on the grizzly or screen E, which will throw rock and largepebbles out of the apparatus, while permitting the water, preciousmetals, and small particles of foreign substance to pass down into thebox D. From the said box the Water, fine sand and the like, and preciousmetals pass through the riffie-sluice, when by reason of the screens Gon the rifiies a large percentage of the small gravel will be preventedfrom gaining access to and clogging the perforations d in theriffie-boards, thus insuring the rapid fiow of water through theapertures d and slots 1) c of the board into the channels 9 beneath thesame and through the said channels. The rapid fiow of water through thechannels 9 of the riffles serves, in conjunction with the zigzag wallsof said channels, to create eddies, and thereby effects theprecipitation of the precious metals. The slots 1) c and apertures 02 inthe boards of the rifl'les permit the free flow of water into and out ofthe zigzag channels g, while the screens G, which practically constitutea continuation of the screen E and form a part of the grizzly, serve, asbefore stated, to prevent sand or particles of ore or loam from cloggingthe said apertures orslots. The screens G also serve to cause the fineparticles carrying precious metals to drag along over the riii'les, sothat when the said particles fall through the screens they will soonfind one of the many apertures or slots in the board a and drop into thezigzag channel below, this being advantageous, since it practicallyrenders it impossible for the most minute particle to escape. If any ofthe small particles of precious metal pass the many turns afforded bythe zigzag form of the channel and are not deposited in such turns bythe eddies due to the rebound of the water, they will bring up againstthe transverse strips of the riffles and remain there, while the lightersmall gravel and sand will be carried over the transverse strips by thestream.

H H are turn-buttons pivotally connected to the side walls of the boxescomprised in the riffle-sluice C and having for their purpose tonormally hold the riffies F down on the bottoms of said boxes, as shownin Fig. 2, and I I are transverse inclined boards which are arranged insuitable cleats on the side walls of the boxes at the opposite ends of abattery of riffies-that is to say, about twelve or fourteen feetapartand are adapted to throw the upper portion of the stream of waterdown, this in order to deflect any small particles that are floating onthe water down to the screens over the riffies and materially lessen theliability of the said parti cles escaping. \Vhen desired, it is obviousthat in lieu of having the transverse strips 6 at the opposite ends ofeach riflie F they may be arranged at the opposite ends of a battery ofriiilesi. 6., twelve or fourteen feet apart without departing from thescope of my invention.

The riftle-sluice is designed to be worked with a strong head of waterabout six inches deep, and the water passing into the channels of eachril'fle must force its way upward at the lower end of such riffie. Whilethis is so, it will be observed that the buttons H will securely holdthe riffles on the bottom of the sluice and prevent the head of waterfrom raising said riffies.

lVhen desirable, in lieu of having the slots 1) c at the opposite endsof each riffle the said slots, like the transverse strips 6, may bearranged at the ends of a batterythat is to say, approximately twelve orfourteen feet apart.

In order to facilitate raising of the rifliles when the riffie-sluice Cis to be cleaned up, I provide the mechanism best shown in Figs. 1 to 3of the drawings. This mechanism comprises levers J, fulcrumed ontransverse bars K on the sluice O and having chains L at their forwardends terminating in hooks M, eyes N on the riffles adapted to be engagedby said hooks, and keepers P, mounted on cross-bars Q, connected to thesluice. When it is desired to raise the riffies, the attendant orattendants have but to raise the buttons H into a horizontal position,place the hooks M in engagement with the eyes N on the riffies, and rockthe levers, so as to carry the rear arms thereof into engagement withthe keepers P, when the riffies will be held in a raised position. Fromthis it follows that all of the riffies in the sluice C may be readilysecured in a raised position and as readily lowered to and secured intheir proper operative positions with but a minimum amount of effort onthe part of the attendant or attendants; also, that when the riffles aresecured in their raised position the stream of water passing through thesluice G will carry with it all the metal or metals deposited in saidsluice and thoroughly clean up the same. Precedent to raising andsecuring the riffies in their raised position with a view of cleaning upthe sluice C, as described, I contemplate interposing a box It betweenthe discharge end of the riffie-sluice and a sluice S, leading to a tankT, which in turn is arranged to discharge into the hopper U of a machinefor separating the precious metals from the fine sand, concentrates, andthe like and collecting the said precious metals. The said machine maybe of any suitable construction; but I prefer to construct it inaccordance with the invention forming the subject-matter of mycontemporary application, filed No vember 20, 1901, Serial No. 82,976,which application constitutes a division of this.

I have entered into a detail description of the construction andrelative arrangement of the parts embraced in the present and preferredembodiment of my invention as a whole in order to impart a full, clear,and exact understanding of the same. I do not desire, however, to beunderstood as confining myself to such specific construction andarrangement of parts, as such changes or modifications may be made inpractice as fairly fall within the scope of my claims.

Having described my invention, what I claim, and desire to secure byLetters Patent, 1s

1. In an apparatus for separating metals from ore, gravel, loam and thelike, a sluice adapted to be connected with a suitable source ofwater-supply and having a riffle comprising a board provided withopenings, longitudinal zigzag walls interposed between the board and thebottom of the sluice and forming tortuous channels in communication withthe openings in the board, means for retarding the flow of water throughsaid channels, and a screen arranged upon the upper side of the boardfor causing the pulp to drag along the riflle and preventing largeparticles from entering the openings of the board.

2. In an apparatus for separating metals from ore, gravel, loam and thelike, a sluice adapted to be connected with a suitable source ofwater-supply and having a riffle susceptible of being raised therein,and comprising a board provided with openings, longitudinal zigzag wallsconnected to the under side of the board and forming tortuous channels,and a screen connected to the upper side of the board and adapted tocause the pulp to drag along the riftle, and also to prevent largeparticles from entering the openings of the board.

3. In an apparatus for separating metals from ore, gravel, loam and thelike, the combination of a conduit, a sluice arranged to receive fromsaid conduit and having a grizzly disposed below the same, and alsohaving rifflesections arranged end to end on its bottom and susceptibleof being raised; the said riffle-seotions respectively comprising aboard having openings, longitudinal zigzag walls connected to the underside of the board and forming tortuous channels, one or more transversestrips connected to and depending from the board, and a screen connectedto the upper side of the board, one or more transversely-disposedinclined boards arranged in the sluice and disposed a slight distanceabove the rit'tle, adjustable devices adapted in one position to retainthe riiile-sections in their operative position on the bottom of thesluice and in another position to permit of the said riffle-sectionsbeing raised, and suitable means on the sluice for raising therifile-sections.

4. In an apparatus for separating metals from ore, gravel, loam and thelike, a sluice adapted to be connected with a suitable source ofwater-supply and having a riffle comprising one or more boards providedat intervals with slots, and also provided intermediate of the slotswith comparatively small apertures, longitudinal tortuous channelsarranged below the board or boards and in communication with the slotsand openings thereof, one or more transverse strips intersecting thesaid channels, and a screen arranged upon the upper side of the board orboards and adapted to prevent rocks and large particles from enteringthe slots and compara tively small apertures therein.

5. In an apparatus for separating metals from ore, gravel, loam and thelike, the combination with a conduit adapted to be connected with asuitable source of water supplyg of a sluice having an arch-shapedscreen or grizzly disposed below the discharge end of said conduit andalso having a rifile compris ing one or more boards provided atintervals with slots, and also provided intermediate of the slots with aplurality of comparatively small apertures, longitudinal tortuouschannels arranged below the board or boards and in communication withthe slots andopenings thereof, one or more transverse stripsintersecting the said channels, and-a screen ar ranged upon the upperside of the board or boards and adapted to prevent rocks and largeparticles from entering the slots and comparatively small aperturestherein.

6. In an apparatus for separating metals from ore, gravel, loam and thelike, a sluice adapted to be connected with a suitable source of supply,and having a riffle comprising a board provided with openings,longitudinal tortuous channels disposed below the board, means forretarding the flow of water through said channels, and a screen arrangedupon the upper side of the board for causing the pulp to drag along therifiile and preventing large particles from entering the openings of theboard, and one or more transversely-disposed inclined boards arranged inthe sluice and disposed a slight distance above the screen.

In testimony whereof I have hereunto set my hand in presence of twosubscribing witnesses.

CYRUS O. PRATT. Witnesses:

J. S. ALLrsoN, L. R. WA'r'rs.

